With disease severity taken into account, estimates of AD prevalence from white populations are more consistent than is usually acknowledged. By including disease severity in the case definition, variations in reported rates are much reduced. The outlier status of the East Boston study appears to result from the use of a definition of AD that differs from that used in the other 20 studies. Alternative explanations of the discrepancy between these estimates and the common estimate of 4 million cases are discussed.

A study of 127 informal caregivers of Alzheimer's disease patients in Florida's Tampa Bay area was undertaken to determine the correlates of the five components of burden, as measured by the Cost of Care Index, a multidimensional measure of caregiving burden. Significant relationships between predictor variables and burden components suggest that global scores and measures of burden do not identify specific problem areas relative to the various components of burden.

Many studies have reported inordinate difficulty in obtaining avoidance learning in discriminated bar-press and related situations, particularly with visual cues (illumination changes) serving as the CS. It is shown that avoidance learning can be substantially increased by dissociating the CS from the manipulandum, which usually occur in close physical proximity. In verification of earlier work, discontinuous shock was again shown to enhance avoidance learning markedly. ProblemA curious fact of discriminated avoidance learning is that, even under seemingly favorable conditions, it often does not occur. Rats given the simple task of pressing a bar (or turning a wheel) in the presenge of a visual CS (change in illumination level) frequently fail to achieve even a modest level of avoidance learning despite extensive training (e. g., D ' Amato & Schiff, 1964; Meyer et aI., 1960). Previous research aimed at uncovering the variables responsible for such failures has shown that discriminated avoidance learning can be greatly facilitated by the use of discontinuous shock, i. e., shock having brief on-periods and longer offperiods (D' Amato et aI., in press). In the present study the contribution of another variable, location of the CS, was investigated. In virtually all bar-press avoidance studies employing a visual cue as the CS the stimulus source is located on the same wall as the bar, requiring S to approach the CS-a secondary aversive stimulusin order to make the instrumental response. Conceivably this is one of the factors which inhibits discriminated avoidance learning in the bar-press and related situations. A second purpose of the study was to determine whether discontinuous shock would continue to enhance avoidance learning when this presumably disrupting factor was 'removed. MethodThe Ss were 34; naive albino rats (13 males), 4-8 mos. of age! drawn from litters bred in our laboratory. Two standard Grason-Stadler Skinner boxes were modified by placing 3 identical I-in. pilot lights on both the front and rear walls of the boxes, making it possible to program the CS (illumination of the pilot lights) to appear on either wall.Group FC (N, 10) was trained with the CS located on the front wall and with conventional continuous shock as the US. Group RC (N, 14) was also trained with continuous shock, but the CS appeared on the rear wall. For Psycho,," &i., 1964, Vol. 1.Group RD (N, 10) the CS was located on the rear wall, while the US was a discontinuous shock.On Day 1 all Ss received 40 avoidance training trials, during which S was shaped on the escape response until a reasonable instrumental response appeared. Group RD received continuous shock during these trials. The CS-US interval was 5 sec.; shock was maintained between .6 and .8 ma; the intertrial interval, programmed by a film tape, averaged about 40 sec. When S failed to avoid, CS and US remained on until terminated by an escape response.On Day 2, 500 training trials were given, the shock level being increased to .8-1.0 mao During these trials Group...

The reliability of the Functional Assessment Inventory (FAI) was evaluated using a sample of VA domiciliary and nursing home patients. The interobserver and interrater reliability coefficients of the summary rating scales, based on a single assessment, tended to be higher than their test-retest reliability coefficients, based on two independent assessments separated by a modal four-week interval. Validity coefficients, using the OARS instrument ratings as criteria, also based on two independent assessments several weeks apart, were, on the average, as high as the test-retest reliability coefficients. More specifically, the mental health, physical health, and activities of daily living rating scales, along with the objectively scored Short Portable Mental Status Questionnaire and Short Psychiatric Evaluation Schedule, tended to yield relatively similar scores with repeated measurement, while the social resources and economic resources scales were somewhat less stable, a discrepancy possibly explained by the homogeneous nature of the social and economic status of most of the patients (institutionalized veterans). Thus the reliability and validity of the FAI are satisfactory, but the stability of some of its scales requires further investigation.